Unions representing Howard County employees have launched an offensive designed to persuade the county executive to back off from his plan to lay off at least 200 government workers and trim the budget by 16 percent.

Dale L. Hill, president of the Howard County Police Officers Association Local 86, is writing residents and business leaders to solicit their help in opposing cuts to the Police Department's budget.

He said union members will talk with people at shopping centers and go door-to-door with a petition that calls for an increase in the current property tax rate of $2.45 per $100 of assessed value. An advertising campaign also is planned.

The union also is calling for citizens to express their objections at public hearings Wednesday and March 11 at the George Howard Building in Ellicott City or to contact County Executive Charles I. Ecker with their concerns about the budget cuts.

At the same time, Council 67 of the American Federation of State, County and Municipal Employees is pressing its 400 members in Howard County to attend the session and express disapproval of the cuts.

"We hope to have more than 200 people show up," said M. C. McPherson, deputy executive director of Council 67, which represents public works and Detention Center employees as well as school system custodial employees.

"We are asking our membership to come out and make their views known," said Mr. McPherson. "We do not believe the process is being fair to public employees."

Mr. McPherson noted that Mr. Ecker has asked the General Assembly for special legislation to allow him to collect his $30,000 pension from the county school board as a retired deputy superintendent and that as executive he got a $20,000 raise to make his annual salary $80,000.

"If money is that tight, why is he asking public employees to lose their jobs or receiveno pay raises, yet the tough financial conditions do not apply to him?" the union official asked.

Mr. Ecker declined to comment on the union official's charge.

But his chief aide, Beverly Wilhide, said Mr. Ecker's pension is"something he contributed to over 36 years" and does not come from county operating expenses. The $80,000 salary, she added, was approved before he took office.

The police officers' union contends that public safety would be diminished by the proposed cuts in which the department would lose 50 positions, including 42 officers.

Officer Hill said the county force should be adding "25 percent more personnel to protect the population we serve" rather than cutting the department's force by approximately 10 percent.

He cited data from the International Association of Chiefs of Police showing the "average for the South Atlantic region of the United States is 2.1 officers per 1,000 residents, while in Howard County the ratio is 1.5 officers per 1,000 residents."

In Baltimore County, Officer Hill said, the average is 2.2 officers per 1,000 residents.

Mr. Ecker said he was not particularly convinced by the statisticscited by the police union because "it is difficult to compare one county to the next, since their services often are not comparable."